Getting focus

Interests:I spend most of my time alpine climbing, hiking, mtn. biking, or skiing. When I can get away it is to travel for climbing or diving. Been doing this nonsense for way too long to do anything different.

Posted 24 February 2011 - 09:04 AM

I am having focus issues and trying to figure out what I can do to improve the situation. I am not sure how much I can attribute it to the fact that during our last trip vis was pretty poor and I just needed to get closer. Or the fact that we had a lot of surge and trying to stay stationary was difficult.

I am having focus issues and trying to figure out what I can do to improve the situation. I am not sure how much I can attribute it to the fact that during our last trip vis was pretty poor and I just needed to get closer. Or the fact that we had a lot of surge and trying to stay stationary was difficult.

Definitely you need to get closer.
Try to select smaller subjects, that way you can get closer.

You can get closer to the damel fish, but the Goliath and the sea star are too big for the lens and port that you are using, because of the size of the subject you need to take some distance.
Not enough artificial light and too much water column between you and the subject.

I am having focus issues and trying to figure out what I can do to improve the situation. I am not sure how much I can attribute it to the fact that during our last trip vis was pretty poor and I just needed to get closer. Or the fact that we had a lot of surge and trying to stay stationary was difficult.

Surge, trouble staying in the desired location, poor vis all sound like tough conditions for photography. In Martin Edge's books, he mentions a very telling story. He followed students, taking photo's of what they selected. The goal was to show how much better it could be done. But his photo's were not that striking either. He discovered an important point. The students (and most of us) are poor at selecting the right subjects for photography. I learned a lot from that book.. you might give it a try.

You might try subjects that you can approach closer and illuminate better...just as mentioned by those above. Which also may mean trying to obtain conditions that are missing the surge, poor vis, etc. You may not be able to control all those factors but perhaps you can work on some of them based on your timing or location selection.For example: rather than trying for the whole star, get close, select an interesting portion of the star and an interesting angle, illuminate it well - which is a lot easier when being close, then see how it turns out. Maybe try different angles with the lighting to see what works and what you like - which you can do with the slow moving subject and when you are really close.Just a thought.

Interests:I spend most of my time alpine climbing, hiking, mtn. biking, or skiing. When I can get away it is to travel for climbing or diving. Been doing this nonsense for way too long to do anything different.

Posted 26 February 2011 - 12:32 PM

Thanks, everyone that helps - get closer. Too much crap between me and the subject for the lens to focus.

The idea of sea star close up did not strike me. But oddly enough while in Palau I did that with a giant clam. The clam was okay but getting up close to is opening and capturing the pattern in the membrane was much better.

You are not getting much light on the subject. Try shooting a single subject and try to be within 1-2 feet of the subject and not shoot into the reef-no contrast with the subject. Understand, however, that poor light, dirty water and surge are not condusive to good pictures.

As a general approach, I guess getting closer is a good recommendation. But, whatabout if the OP is not into macro photography and wants to include much of the environment and scenery?

The sea star is a good example of this. I think this picture has a reasonable amount of justifiable light and does not look studio lit. Couldn't the problem then just be exposure time vs available light, i.e. lack of sharpness could be caused by slight movement due to surge or camera shake whilst triggering? Slightly different framing and some postprocessing could otherwise improve the picture, but, the focus problem remains.

With the hawk fish, I might have tried 20-30% closer to get rid of the white coral on the right. With the grouper, one might have tried just a bit closer still with the composure. But I guess it would not have made a big difference under the lighting and visibility conditions.

The Leica is a small camera with probably a rather light weight housing. Given the flat lighting, poor visibility and limitations of the optics and sensor, one might not expect much better results. You might try to add some stabilizing arms or anything else to give momentum to the housing. Also practice on having a good dual hand grip and remaining as motionless as possible when shooting. Is your buoyancy perfect or do you need to keep finning?

As a general approach, I guess getting closer is a good recommendation. But, whatabout if the OP is not into macro photography and wants to include much of the environment and scenery?

The sea star is a good example of this. I think this picture has a reasonable amount of justifiable light and does not look studio lit. Couldn't the problem then just be exposure time vs available light, i.e. lack of sharpness could be caused by slight movement due to surge or camera shake whilst triggering? Slightly different framing and some postprocessing could otherwise improve the picture, but, the focus problem remains.

With the hawk fish, I might have tried 20-30% closer to get rid of the white coral on the right. With the grouper, one might have tried just a bit closer still with the composure. But I guess it would not have made a big difference under the lighting and visibility conditions.

The Leica is a small camera with probably a rather light weight housing. Given the flat lighting, poor visibility and limitations of the optics and sensor, one might not expect much better results. You might try to add some stabilizing arms or anything else to give momentum to the housing. Also practice on having a good dual hand grip and remaining as motionless as possible when shooting. Is your buoyancy perfect or do you need to keep finning?

Definitely being motionless is one of the key for low light pictures.Las year the slowest shot I was able to take was 1/50th, lower than that the results was not acceptable. Last weekend I was able to take a shot to a shoal of fish at 1/30th and the nearest fishes was totally in focus, maybe my intro to cave training in Mexico at the end of 2010 is related to this.

In general your pictures don't look out of focus too much but the focus seems not to be on the subject or the subject is a too little part of the picture o

Did you use autofocus with some form of AI? I find that switching off AIAF and any metering based on matrix works best in close up. I use center weighter or spot focus together with AIAF off to make sure the focus is in the center

The further away you are more there is a chance that particles disturbs your focus, plus if you are too far and the light is really low the camera may struggle to focus entirely. So either use a focus light or get closer or use manual focus or focus lock (essential when you have crap in the water)

Definitely being motionless is one of the key for low light pictures.Las year the slowest shot I was able to take was 1/50th, lower than that the results was not acceptable. Last weekend I was able to take a shot to a shoal of fish at 1/30th and the nearest fishes was totally in focus, maybe my intro to cave training in Mexico at the end of 2010 is related to this.